1. Field of the Invention
The present invention is related to an active device array substrate, and more particularly, related to an active array substrate capable of preventing open circuit of signal lines during testing processes.
2. Description of Related Art
Thin film transistor liquid crystal displays (TFT-LCD) have become a mainstream product in the display market due to high image quality, great space efficiency, low power consumption, and no radiation. During the processes of fabricating liquid crystal display panels, testing processes are performed necessarily so as to ensure the liquid crystal display panels are capable of operating normally. Generally, shorting bars are adapted to test the liquid crystal display panels. Generally, during the testing processes of the liquid crystal display panels, a testing signal is input to all the scan lines simultaneously through a gate shorting bar electrically connected to the scan lines so as to enable all the pixels. Then, red, green and blue testing signals transmitted by a plurality of source shorting bars are respectively input to all the pixels through connecting conductors and data lines. After the testing signals are input to the pixels, the liquid crystal display panels are observed so as to determine whether the liquid crystal display panels display normally.
When the above-mentioned testing processes are performed, line defects are usually detected. However, the line defects are not absolutely resulted from broken data lines or broken scan lines. Under some situations, the line defects result from open circuit of the connecting conductor(s) electrically connected between the data lines and the source shorting bars or electrically connected between the scan line and the gate shorting bar. Specifically, in the first three columns of pixels (or namely the forward three columns of pixels, or namely the preceding three columns of pixels), the above-mentioned line defect phenomenon usually occurs, wherein each one of the first three column of pixel within one data line. Since testing signals having excess current (i.e. red, green, and blue testing signals) are applied during the testing processes of the liquid crystal display panels, the connecting conductors connected between the first three data lines (or namely the forward three data lines, or namely the preceding three data lines) and the source shorting bars are usually broken. In order to prevent the broken phenomenon of the connecting conductors occurs in the first data line within the first pixel (or namely the most outside data line in the most outside pixel, or namely the outset data line in the outset pixel) again and again, a prior art solution is provided. The prior art solution is illustrated in FIG. 1A and FIG. 1B.
FIG. 1A is a top view of a prior art testing circuit. FIG. 1B is an equivalent circuitry of the prior art testing circuit shown in FIG. 1A. Referring to FIG. 1A and FIG. 1B, the layout of the 1st data line DL1, the 2nd data line DL2, and the 3rd data lines DL3 in the prior art testing circuit 100 is modified so as to reduce the broken phenomenon of the connecting conductors 120. Specifically, an end of the 1st data line DL1 branches and is electrically connected to the shorting bar 110 through two connecting conductors 120; an end of the 2nd data line DL2 branches and is electrically connected to the shorting bar 110 through two connecting conductors 120; and an end of the 3rd data lines DL3 branches and is electrically connected to the shorting bar 110 through two connecting conductors 120. However, referring to the equivalent circuitry in FIG. 1B, testing signals having excess current are still applied to the 1st data line DL1, the 2nd data line DL2, and the 3rd data lines DL3 during the testing processes of the liquid crystal display panels. Accordingly, the branch design of the ends of the 1st data line DL1 , the 2nd data line DL2, and the 3rd data lines DL3 is not effective to reduce the probability of the broken phenomenon of the connecting conductors 120. The broken phenomenon of the connecting conductors 120 marked in a circle in FIG. 2A and FIG. 2B is serious. The position A′ shown in FIG. 1A is corresponding to the portion marked in a circle shown in FIG. 2A while the position A″ shown in FIG. 1B is corresponding to the portion marked in a circle shown in FIG. 2B.
Therefore, how to reduce the probability of the broken phenomenon of the connecting conductors 120 effectively during the testing processes of liquid crystal display panels is an important issue.